1. Field of the Disclosure
This disclosure relates generally to a treating formation zones, including fracturing, gravel packing and flooding.
2. Background of the Art
Wellbores are drilled in subsurface formations for the production of hydrocarbons (oil and gas), which are trapped in various traps or zones in the subsurface formations at different wellbore depths. Such zones are referred to as reservoirs or hydrocarbon-bearing formations or production zones. A casing is generally placed inside the wellbore and the space between the casing and the wellbore (annulus) is filled with cement. A completion string or assembly containing a number of devices is placed inside the casing to perform a variety of operations downhole, including, but not limited to, fracturing, gravel packing and flooding zones with a fluid supplied from the surface. Typically, the completion assembly includes an outer assembly and an inner or service assembly placed inside the outer assembly to treat the wellbore zones. The outer assembly typically contains a variety of devices, such as packers to isolate zones, flow port devices to provide fluid communication between inside of the outer assembly and the formation, sand screens for preventing or mitigating flow of solid particles above a certain size from the formation to the inside of the outer string. The inner assembly contains devices to open and close or operate a number of devices in the outer assembly and to provide a fluid path from the surface to the outer assembly. To treat a zone, the treatment fluid is supplied to the inside of the inner assembly, which is supplied to the formation via a port in the inner assembly and another port in the outer assembly. This single fluid path provides an upper limit to the amount of the treatment fluid that can be supplied to a zone.
The disclosure herein provides apparatus and methods for supplying a treatment fluid to a zone via more than one fluid path to increase the rate of the supplied fluid.